1. Field of the Invention
The present invention relates to an auto changer apparatus for a recording medium, which has a number of recording media and sequentially installs a selected one of the media in an archiving/retrieving unit and, more particularly, to a control system for the archiving/ retrieving data.
2. Description of the Related Art
In such an auto changer apparatus, a recording medium is replaceable with respect to the archiving/ retrieving unit, and which medium is installed and when it is installed are unknown. Therefore, upon installment of each medium in the archiving/retrieving unit, defect control data of the installed medium is read out from the medium, and a pre-process such as substitute processing of a defective track for a normal track is performed. The pre-process includes making of a directory in addition to the above processing. Thus, in a conventional auto changer apparatus, access must be started in practice after the defect control data is read out from a medium upon installment of the medium in the archiving/retrieving unit and a pre-process is performed. Therefore, when replacement of the recording medium is frequently performed, and a large number of recording media are accessed, a ratio of a time period required for performing the pre-process with respect to the total access time is increased, and hence an access time is undesirably prolonged.